JP-A No. 2006-118512 discloses a structure where an oil control valve, which controls hydraulic pressure applied to an actuator of a hydraulic valve timing changing mechanism for changing operation modes of engine valves, is mounted on a chain cover that covers a cam chain wound around a driving sprocket of a crankshaft and driven sprockets of camshafts.
In the structure disclosed in JP-A No. 2006-11852, oil passages, which connect the oil control valve with the actuator of the valve timing changing mechanism, need to be disposed across a cam chain chamber, which is formed in an engine body to move the cam chain, so as to avoid the cam chain. For this reason, it is not easy to dispose the oil passages, and the degree of freedom in disposing the oil passages is decreased. Further, pipe members, which are individual bodies separated from the engine body, need to be disposed across the cam chain chamber, causing the number of parts and assembly man-hours to be increased.